docs: def load(self, filename):
          """
          Load AEAD from a file.
  
          @param filename: File to read AEAD from
          @type filename: string
          """
          aead_f = open(filename, "rb")
          buf = aead_f.read(1024)
          if buf.startswith(YHSM_AEAD_CRLF_File_Marker):
              buf = YHSM_AEAD_File_Marker + buf[len(YHSM_AEAD_CRLF_File_Marker):]
          if buf.startswith(YHSM_AEAD_File_Marker):
              if buf[len(YHSM_AEAD_File_Marker)] == chr(1):
                  # version 1 format
                  fmt = "< I %is" % (pyhsm.defines.YSM_AEAD_NONCE_SIZE)
                  self.key_handle, self.nonce = struct.unpack_from(fmt, buf, len(YHSM_AEAD_File_Marker) + 1)
                  self.data = buf[len(YHSM_AEAD_File_Marker) + 1 + struct.calcsize(fmt):]
              else:
                  raise pyhsm.exception.YHSM_Error('Unknown AEAD file format')
          else:
              # version 0 format, just AEAD data
              self.data = buf[:pyhsm.defines.YSM_MAX_KEY_SIZE + pyhsm.defines.YSM_BLOCK_SIZE]
          aead_f.close()